中文摘要：

提出了一种组蛋白乙酰化修饰检测的耦合增强拉曼散射生物传感新方法.该方法以金纳米粒子为表面增强拉曼散射（SERS）基底,表面修饰乙酰化组蛋白H3多肽为识别探针,对甲氧基苯硫酚（4-MTP）为拉曼标记物,制备了组蛋白乙酰化修饰检测的SERS纳米探针.通过紫外可见吸收光谱与动态光散射分析,证实了组蛋白乙酰化抗体可介导SERS纳米粒子发生可控组装与聚集,使SERS纳米探针间发生局域电场共振耦合,产生显著增强的SERS信号.基于此,通过待测抗原与SERS纳米探针对抗体的竞争性相互作用,我们设计了组蛋白乙酰化修饰检测的竞争免疫SERS生物传感方法.该法操作简便、快速、重现性好,且裸眼即能进行可视化鉴定.通过设计不同染料标记的SERS纳米探针,该法有望实现多种组蛋白修饰的复合检测.

英文摘要：

A new biosensing approach is developed for the detection ofhistone acetylation using a surface-enhanced Raman scattering （SERS） nanoprobe constructed by decorating gold nanoparticles （AuNPs） with acetylated histone H3 peptide and 4-MTP. Using absorption spectrum and dynamic light scattering analysis, we observe acteyl-histone antibody is able to me-diate a network-like assembly of SERS nanoprobes, and strong plasmonic coupling between AuNPs is thus induced with a remarkably enhanced SERS signal. Based on this finding, we report the proof-of-principle of a competitive immunoassay biosensor for acetylated histone via the competitive interactions of acteyl-histone antibody with target antigen and SERS nanoprobe. In the absence of acetylated histone, the binding of acetylated H3 peptide to its antibody triggers the assembly of the SERS nanoprobes and thus induces a strong SERS signal. The presence of target antigen, which will competite for binding sites of the antibodies, disables the binding of acetylated H3 peptide to its antibody, prevents the assembly of the SERS nanoprobes and thus merely generate a weak SERS response. The results reveal that the developed biosensor has high sensitivity for detecting the acetylated histone. A linear correlation is obtained for the SERS signals to the logarithmic acety- lated histone concentration ranging from 0.5 nmoloL-l to 200 nmoloL-I with a detection limit of 0.5 nmoloL-1. Additionally, the design of the biosensor allows a visual and homogeneous assay of the acetylated histone with no need of antibody label- ing, which affords improved assay simplicity and throughput. This biosensor strategy may provide a convenient, rapid, highly sensitive and selective, homogeneous platform for histone acetylation assay. With the use of different Raman dyes and pep- tides, this biosensor might be further developed for multiplexed assays of different histone modifications.